OC中的NSNumber

//声明一个整数
    NSInteger a=9;
    //创建常见的数据类型的对象
    NSNumber *intNumber=[[NSNumber alloc] initWithInt:5];
    NSNumber *floatNumber=[[NSNumber alloc] initWithFloat:5.14f];
    NSNumber *doubleNumber=[[NSNumber alloc] initWithDouble:5.14];
    NSNumber *charNumber=[[NSNumber alloc] initWithChar:'C'];
    
    //NSNumber是一个类簇，可以创建各种数据类型的对象
    
    NSNumber *intNumber=[NSNumber numberWithInt:6];
    //比较是否相等：不同类型之间也可以相比较
    BOOL ret=[intNumber isEqualToNumber:intNumber2];
    BOOL ret=[intNumber isEqualToNumber:floatNumber];
    //比较大小:
    if([intNumber compare:intNumber2]==NSOrderedAscending){
        NSLog(@"<");
    }else if([intNumber compare:intNumber2]==NSOrderdSame)
    {
        NSLog(@"=");
    }else if([intNumber compare:intNumber2]==NSOrderdDescending){
        NSLog(@">");
    }
    //输出
    NSLog(@"%d",[intNumber intValue]);
    NSLog(@"%f",[floatNumber floatValue]);
    NSLog(@"%f",[doubleNumber doubleValue]);
    NSLog(@"%c",[charNumber charValue]);
    //释放
    [intNumber release];
    [floatNumber release];
    [dobuleNumber release];
    [charNumber release];